Fluid cylinder assembly



Aug. 27, 1968 J. s. MILLER ,3,398,652

FLUID CYLINDER ASSEMBLY y Original Filed June 25, 1963 5 Sheets-Sheet l z Q EE Q l U L\ I E Qi TUCK ENTQY POTION INVENTOR. +P@ dol-m 5. M\LLE.R

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A Tram/ys Aug 27, 1958 J. s. MILLER FLUID CYLINDER ASSEMBLY 5 Sheets-Shee'(l 2 INVENTOR.

BIQHN S. M1LLER Original Filed June 25, l9-

A TPO/QAM y5 Aug. 27, 1968 J. s. MILLER FLUID CYLINDER ASSEMBLY 5 Sheets-Sheet 4 Original Filed June 25, 1963 INVENTOR. M\LLER MMM/ 4' AT/Uvf/f Q25 Teb d 95@ mm da; ,zmmNJ` ma .55 tbw# www@ il, l x f f l w ff/ /v N? f J. S. MILLER Aug. 27, 1968 FLUID CYLINDER ASSEMBLY Original Filed June 25, 1963 5 Sheets-Sheet 5 INVENTOR. lgcnm S.M\LLER Afro/w05 United States Patent 3,398,652 FLUID CYLINDER ASSEMBLY John S. Miller, Poland, Ohio, assgnor to The McKay Machine Company, Youngstown, Ohio Original application June 25, 1963, Ser. No. 290,454, now Patent No. 3,266,283. Divided and this application Mar. 8, 1966, Ser. No. 553,591

3 Claims. (Cl. 92-165) ABSTRACT F THE DISCLQSURE A piston and rod assembly operating within a cylinder with a non-marring material covering the rod in the radial space between the rod and the cylinder. The piston rod has universal tilting movement with respect to the piston. Fluid bathing means is provided to remove deleterious material from the piston rod.

This application is a division of Ser. No. 290,454, led June 25, 1963, now Patent No. 3,266,283.

The present invention relates to a drawbench, more particularly to a drawbench of the hydraulic type and to subassemblies particularly adapted for use therewith, and the principal object of the invention is to provide new and improved devices of the character described.

As generally known in the trade, a drawbench is a device for drawing elongated stock, such as a rod, through a die in order to effect a transverse reduction in the size of the stock. In many cases, a powerful hydraulic cylinder is employed to pull the stock through the die.

Since the stock to be drawn is initially of considerable length, since such length is materially increased as a result of the drawing operation, and since a hydraulic cylinder having a stroke at least as long as the stock after drawing must be employed, the normally constructed drawbench tends to require a considerable length of floor space. For example, and as will later appear, a conventional drawbench for drawing 20 foot stock to a length of 25 feet will require more than 70 feet of floor space. In contrast, by the use of the present invention, a saving of about 20 feet of floor space length can be eifectuated with no decrease in stock capacity.

Additionally, since the present invention utilizes the greater force application effectiveness of a hydraulic cylinder on its out-stroke rather than on its in-stroke as is conventional, a smaller diameter hydraulic cylinder and/or less hydraulic pressure and Volume may be employed with considerable cost savings. These and other advantages will readily become apparent from a study of the following description and from the drawings appended hereto.

In the drawings accompanying this specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which the invention may assume, and in these drawings:

FIGURE 1 is a side elevational view of a preferred embodiment of the invention,

FIGURE 2 is a top plan View thereof,

FIGURE 3 is an enlarged plan view, partially in section, and generally corresponding to the line 3-3 of FIGURE 1,

FIGURE 4 is an enlarged plan view, partially in section, and generally corresponding to the line 4 4 of FIG- URE 1y FIGURE 5 is a still further enlarged, fragmentary sectional view generally corresponding to the line 55 of FIGURE 2,

FIGURE 6 is a sectional View generally corresponding to the line 6-6 of FIGURE 4,

FIGURE 7 is a reduced size, generally diagrammatic view similar to FIGURE 1, and

FIGURE 8 is a view similar to FIGURE 7 and to the same scale but of prior art apparatus.

With reference to FIGURES 1 and 2 and for convenience of disclosure, the apparatus herein illustrated may conveniently be divided into a die station A, a stock entry portion B to the left of the die station, and a stock drawing portion C to the right of the die station. Associated with the stock entry portion B is a stock entry table 10 and interposed between the latter and the die station A is a stock entry carriage 11 having a relatively short path of travel toward and away from the ydie station. To the right of the die station, the stock drawing portion C provides a draw carriage 12 shown adjacent the die station but shiftable from such position to the extreme right-hand end of the apparatus. As will later be disclosed in greater detail, each carriage 11, 12 is provided with jaws for gripping the stock to be drawn through the die station A.

In brief, operation of the apparatus thus far described will be as follows: The stock to be drawn will be placed on the stock entry table 10 with its right-hand end adjacent the die station. The stock entry carriage will next grip the stock and will then be shifted to the right to force the stock end through the die station far enough to permit it to be gripped by the stock drawing carriage 12. After the stock drawing carriage 12 has gripped the stock, such carriage will be shifted to the right to draw the remainder of the stock through the die station thus completing the drawing operation. With the drawing operation completed, the stock will be released by the carriage 12 for removal thereof from the apparatus. Both carriages may now be returned to the positions shown in FIGURES l and 2 ano the foregoing operations repeated on another piece of stock.

Still referring to FIGURES 1 and 2, the means for effecting movement of carriage 12 to the right comprises a pair of elongated fluid cylinder assemblies 13 in spacedapart, side-by-side relation. As will later be disclosed in greater detail, the right-hand end of each cylinder assembly is secured to respective upright ears 14 of a frame structure 15 whose other end provides upright ears 16 forming a part of the die station A. The left end of each cylinder assembly 13 is supported on a stanchion 17, similar stanchions 18 being interposed between stanchions 17 and the frame 15 and spaced along the cylinder assemblies to support the latter. Stanchions 18 may also conveniently be employed to support the stock entry table 10.

Turning now to FIGURE 5 wherein the left-hand end of one of the cylinder assemblies 13 is illustrated, it is to be understood that both cylinder assemblies are preferably identical and thus only one need be shown and described in detail. As presently disclosed, cylinder assembly 13 comprises an elongated cylinder barrel 19 whose righthand end is anchored to a frame ear 14 by means later to appear. The left-hand end of the barrel 19 is suitably closed by an end plug 20 to which is connected a conduit 21 through which fluid may pass into and out of the cylinder barrel.

Slidable in the cylinder barrel is a piston 22 carrying suitable sealing rings 23 and secured to the right-hand end of piston 22 is a tubular piston rod 24. In the present embodiment, a stud 25 has an enlarged end 26 suitably anchored to the piston rod 24 and a shank portion 27 extending through an enlarged central aperture 28 in the piston. Such aperture is reduced in size at the left of the piston and an O sealing ring 29 prevents the escape of fluid between the piston and the stud. The extreme lefthand end of stud 25 is threaded to receive a pair of nuts 30 which retain the piston assembled on the stud.

It is an important feature of the present invention that the ends of piston 22 are spherical and are seated against respective complementarly formed washers 31, 32 assemforce on the piston tending to cock it in its cylinder bore.

Obviously, because of the great length of the piston rod, it will have a tendency to ldeflect, even of its own weight, a small but significant amount.

Since piston rod 24 is subjected to compressive forces, rather than tension forces, during the stock drawing operation, it is important that the piston rod be of maximum size to resist any tendency to buckle. Accordingly, the piston rod is herein shown to have a transverse size but slightly smaller than the bore of the cylinder barrel 19. With such a piston rod to cylinder bore relationship and with such a long piston rod, transverse deflection of the rod could cause it to rub along and scratch the cylinder barrel. To eliminate this possibility, the piston rod is presently covered with sleeves 33 of non-ferrous, relatively soft material in end-to-end, abutting relation. Such sleeves may be formed of a suitable plastic or a soft metal such as babbit. Although not shown, a slight operating clearance will be provided between the exterior of the sleeves 33 and the bore of the cylinder barrel 19.

Referring now to FIGURE 3, the right-hand end of the cylinder barrel 19 is externally threaded to receive a shouldered sleeve 34 and the latter is tightly clamped against the frame ear 14 by means of a nut 35 threaded on the sleeve. Seated against the right-hand end of sleeve 34 and concentric with the cylinder barrel 19 is a hollow piston rod 36 through which the piston rod 24 passes. Here again, operating clearance over the piston rod sleeves 33 will be provided. Hollow piston rod 36 is rmly clamped against the sleeve 34 by means of a split collar 37 bolted to the frame ear 14 and having a radially inwardly projecting flange seated in an annular groove formed in the rod 36.

For a purpose later to appear, the end of hollow piston rod 36 adjacent the cylinder barrel 19 has an enlarged bore portion in which is seated a flexible, annular wiper member 38 encircling and engaged with the exterior of the covered piston rod 24. Adjacent this wiper and on the side thereof away from the cylinder barrel 19 is an annular recess 39 surrounding the piston rod 24. A conduit 40 places recess 39 in communication with a source of pressurized iluid.

The right-hand end of the hollow piston rod 36 is reduced in diameter and passes through a close-iitting aperture in a frame ear 16 and is externally threaded to receive a nut 41 which clamps the rod iirmly in position. Enclosing the right-hand end of hollow piston rod 36 is an axially elongated collar 42 bolted to the ear 16. 'I'he interior of collar 42 carries an annular wiper member 43, similar to 38, and provides an annular recess 44, similar to recess 39. A drain conduit 45 carries uid away from recess 44 and returns it to the pressure source connected to the previously described conduit 40.

Turning next to FIGURE 4, it will be noted that the piston rod 24 extends beyond the die station A and is secured to the draw carriage 12 by any suitable means, such as, for example, the flat-head capscrews 46. Carriage 12, therefore, spans the piston rods 24 of the two cylinder assemblies 13 (see FIGURE 6) and ties them together for unitary movement.

In order to guide the piston rods 24 as they are shifted to the right from the position seen in FIGURES 3 and 4, each is contained within an elongated, tubular member 47 which provides a small radial operating clearance over such piston rod. Such members 47 serve a multiple purpose in that they not only function to guide the rods, but also support them against buckling and protect them from dirt and the like. As best seen in FIGURE 4 wherein one of the members 47 is shown in section, each member is secured to a respective collar 42 by means of a suitable collar 48 and each extends therefrom the full length of the apparatus drawing portion IC and has its free end supported lby an overhanging stanchion 49 (FIGURES 1, 2 and 6). Additional, identical stanchions 50 are interposed between the stanchion 49 and the frame 15 and are spaced along the members 47 for adequate support thereof. AS best seen in FIGURE 6 and since the carriage 12 extends between the ends of the piston rods 24, the facing sides of the tubular members 47 are cut away to pass the carriage. At each of the stanchions S0, 49, a conduit 51 provides for the return of oil in a manner similar to the conduits 45 previously described.

Returning once again to FIGURE 3, it will be noted that the hollow piston rod 36 has an integrally formed piston 52 intermediate its ends. Slidable along the piston rod 36 and cooperable with the piston S2 is a cylinder lbarrel 63 having the usual seal structure at each end for sealing about respective, adjoining piston rocl portions. Conduits 54, 55 provide for passage of fluid to the interior of the bore of cylinder barrel 53 on opposite sides of the piston 52. In the foregoing it will now be clear that the piston rod 36, piston 52 and cylinder barrel 53 constitute a cylinder assembly which is reversed from the ordinary assembly in that the piston and its rod are held stationary while the cylinder barrel is shiftable axially of the piston rod. The cylinder barrel 53 and all the other associated parts hereinabove described are, of course, duplicated on the opposite side of the apparatus.

The previously mentioned stock entry carriage 11 is herein shown integral with the cylinder barrels 53 and is provided with opposed jaws 56 for gripping the stock S shown in phantom lines. Although not shown, a suitable actuating mechanism may be employed to effect jaw movement to grip and release the stock. Similarly, and with reference to FIGURE 4, the stock drawing carriage 12 will be provided with opposed jaws 57 for gripping the stock. Here again, suitable means may be provided for etiecting jaw movement to grip and release the stock. Completing the structure and referring to FIGURES 3 and 4, a die 58 will be suitably mounted at the die station A. For example, the die may carry opposed lugs 59 which t closely within respective slots formed in the frame ears 16.

With the parts positioned as illustrated in FIGURES 1 through 5 and with the carriage jaws 56, 56 and 57, 57 separated, a piece of stock S will be pushed between the jaws 56 of the stock entry carriage 11 and into abutment with the die 58. Jaws 56 will now be actuated to clamp the stock and fluid under pressure admitted through the conduits 55 to cause the cylinder barrels 53 and the associated carriage 11 to move toward the die 58. Movement of carriage 11 as above described will force the end of the stock through the die 58 far enough so that the stock can be gripped by the carriage jaws 57 as illustrated in FIGURE 4. Jaws 57 will next lbe actuated to grip the stock while the jaws 56 will be released therefrom. Carriage 11 may, if desired, be returned at this time to the position seen in FIGURE 3 by admitting tluid pressure through conduits 54.

With the stock being gripped bythe jaws 57, iluid under pressure will be admitted through conduits 21 to thus shift the pistons 22, the piston rods 24 and the carriage 12 to the right. Movement of the carriage 12 in this direction will draw the stock through the die 58 as will be understood. When the entire length of stock has been drawn through the die 58, jaws 57 will be shifted to release the stock whereupon the latter can drop free of the apparatus.

During t-he foregoing operational sequence, oil under pressure will be continuously supplied through the conduits 40 to each of the recesses 39. Such oil will then liow along the exterior of each piston rod 24 to lubricate the latter as they move to the right. The majority of such oil will be recovered by the recesses 44 and the conduits 45; however, any excess oil drawn along with the piston rods will be returned to its source through the conduits 5S at respective stanchions 50, 49. i

Following the drawing operation hereinabove described, the carriage 12 will be at the extreme right-hand end of the apparatus and, since the cylinder assemblies 13 which effect its movement are single acting, separate mean (not shown) will be employed to rreturn this carriage to the position seen in FIGURE 4. This may readily be accomplished by, for example, a fluid cylinder having cable connection with the carriage or by an electric motor having driving connection with a chain which s in turn connected to the carriage. Various other expedients may as well be used, it being understood that relatively little force will be required to so return the carriage.

Regardless yof the means used to return the carriage, it will be understood that such operation causes the piston rods 24 to move to the left, the wipers 43, 38 wiping the rods free of any foreign matter and the continuous oil flow flushing the rods and carrying away any such foreign matter. Accordingly, as the piston rods are retracted into their cylinder barrels 19, they will be cleansed so as not to draw foreign matter into the barrels. With the carriage 12 positioned once again as seen in FIGURE 4, another stock drawing cycle may be commenced.

As earlier mentioned, a major advantage of the present draw-bench over those heretofore known is a considerable reduction in space requirements. This is accomplished by the hereinabove disclosed disposition of the draw carriage cylinder assemblies on the entry side of the die stand, or station, in superposed relation with the entry table, rather than on the exit side of the die stand.

FIGURE 7 illustrates the present invention wherein there is shown a drawbench for receiving foot lengths of stock and for drawing such stock to a length of 25 feet. In order to draw the stock to a length of 25 feet, carriage travel of 25 feet will be required (ignoring, for present purposes, a certain amount of carria-ge overtravel which must normally be provided). With an assumed carriage travel of 25 feet, each carriage shifting cylinder must have la travel of 25 feet. Note in FIGURE 7 that the 25 foot stroke carriage actuating cylinder is disposed on the entry side of the die stand in superposed relation with the 20 foot entry table. Thus, the apparatus requires a total of 55 feet of floor space if the die stand is assumed to require 5 feet of space.

In contrast and referring to FIGURE 8, prior-art apparatus of the same capacity requires the same 20 foot entry table, the same 5 foot die stand, the same 25 feet of carriage travel, 'and the same 25 foot stroke, carriage actuating cylinder. However, since the prior-art, carriageactuating cylinder is disposed on the exit side of the die stand, a total of 75 feet of door space is required. Clearly,

this is 2O feet more floor space than is required by the presently disclosed, novel apparatus.

In view of the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modiiied, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specically described; hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim:

1. An elongated Huid cylinder assembly comprising an elongated cylinder barrel,

a piston closely fitting within the bore of said cylinder barrel and slidable longitudinally thereof,

a piston rod connected to and movable with said piston and projecting axially outwardly of one cylinder barrel end, the diameter of said piston rod being materially less than that of said piston to provide a radial space between said rod and said cylinder barrel bore, `and a non-marring material disposed in the radial space aforesaid and such material being movable in unitary relation with said piston and said piston rod and covering vat least that portion of the latter which is disposed `within said cylinder barrel when said piston is at the other cylinder barrel end to prevent engagement of said piston rod with said cylinder barrel bore.

2. The construction of claim 1 wherein said non-marring material is softer than the facing surfaces of said cylinder barrel bore and said piston rod.

3. The construction of claim 2 wherein a flexible, annular member is disposed at said one cylinder barrel end for wiping engagement with said non-marring, piston rod covering material.

References Cited UNITED STATES PATENTS 587,36() 8/1897 Carroll 308-4 XR 2,811,397 10/ 1957 Cline 92-249 XR 2,846,943 8/ 1958 Belk 92.-249 XR MARTIN P. SCHWADRON, Primary Examiner. I. C. COHEN, Assistant Examiner. 

